got rid of DomainUtils.createSummary()
restructured associations between domain classes

- Channel#saveWithSummary() is removed
- Channel-Summary: one-to-one (bi); summary is automatically created when Channel is created
- Channel-Person: many-to-many
- Channel-Irclog: one-to-many (bi) without cascading, but on delete set null
- Channel has default values
- ChannelService#getJoinedPersons() and getAllJoinedPersons() are removed because it can be normally available via association
- Tests is fixed according to changing product code
- Test to confirm cascading Channel and other associations is added
- gsp is fixed  according to changing product code
removed SummaryListService because Summary can be get from Channel via association

- sorting is given up
added migration script for v0.3
version 0.3
version 0.4-SNAPSHOT